Problem: The sum of $3$ consecutive integers is $57$. What is the third number in this sequence?
Answer: Call the first number in the sequence $x$ The next integer in the sequence is $x + 1$ The sum of the $3$ consecutive integers is: $x+ (x + 1)+ (x + 2) = 57$ $3x + 3= 57$ $3x = 54$ $x = 18$ Since $x$ is the first number, $x + 2$ is the third integer. Thus, the third number in the sequence is $20$.